Exemplary embodiments herein relate to pressure-sensing and indicating devices for gas systems and, more particularly, to a removable indicator/alarm device for a gas regulator for at least one pressurized gas source such as an L.P. gas tank.
Gas regulators are widely known and used to provide gas at a stepped-down pressure. One type of gas regulator is an automatic changeover two-stage LP gas regulator, such as those made by Cavagna of Italy, as well as other manufacturers. Automatic changeover gas regulators typically comprise a high-pressure changeover regulator and a low-pressure regulator. The high-pressure changeover regulator includes two inlets for receiving gas from two separate pressurized containers, reduces the gas pressure to a first predetermined level, and transmits that gas to the low-pressure regulator. The low-pressure regulator further reduces the gas pressure to a predetermined level prior to conveying the gas through an outlet to, for example, a selected appliance.
In many applications, and particularly in the recreational vehicle field, at least two gas source containers (a “supply” container and a “reserve” container) are connected to at least two corresponding inlets of the high-pressure changeover regulator. Each inlet receives gas from a different gas source container. During use of the connected appliance, when the supply container becomes depleted of gas, the regulator automatically changes over to the reserve container such that the reserve container becomes the “new supply” container for providing gas to the regulator. After the changeover, the original supply container can be disconnected from the corresponding inlet of the regulator and be replaced or refilled.
To notify the user of a changeover to the reserve container, known regulators of this type have a mechanical gauge, such as a full/empty indicator, attached to the high-pressure regulator for visually indicating a pressure of the gas received through the inlet associated with the supply container. This full/empty indicator typically includes a pressure-sensitive member, for example, a diaphragm, that is responsive to the gas pressure. The full/empty indicator also typically includes a bi-colored or similar indicator member that is mounted and displayed in a transparent capsule attached adjacent to the high-pressure changeover regulator. The indicator member abuts or is coupled to the diaphragm. As the diaphragm moves (i.e., deflects) in response to changes in pressure, the diaphragm exerts a force on the bi-colored indicator member. As a result, the diaphragm causes movement of the indicator member to display a portion of the indicator member having a color indicative of the “full/empty” status of the supply container. For example, when the supply container is generally depleted of gas after extensive use, the low gas pressure sensed by the diaphragm causes the diaphragm to deflect accordingly and thus cause corresponding movement of the bi-colored or other indicator member to display a portion of such indicator member which shows that the supply container is empty and should be disconnected.
A shortcoming of such mechanical full/empty indicators is that the gas regulator and gas containers are typically stored at a remote location, or are hidden from view. Since the supply system is usually placed out of the way, the gauge or full/empty indicator is not ordinarily visible. As such, the user has to go out of his way to inspect the gas cylinders, including the gas regulator and indicator attached thereto, to determine whether the automatic changeover has been triggered. Since the changeover is automatic and only occurs at spaced intervals and on an irregular basis, and may occur at night, the condition may go undetected for some time, leading to unexpected depletion of the reserve container.
Therefore, an indicator/alarm device is needed that conveniently notifies the user that the supply container is at or near empty, such that the user does not have to continuously and unnecessarily check the full/empty status of the gas container(s) at their remote location.